510(k) · Cleared
ClearedMonarch 21 Penile Plethysmograph System
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Behavioral Technology, Inc. · LIL Monitor, Penile Tumescence
Cleared on Oct 29, 2003 as substantially equivalent to K936115 (Farrall Instruments, Inc., 1995) after a 29-day review. Its family tree reaches back 1 generation to 1995. 1 later device descends from it.
- Decided
- Oct 29, 2003
- Review
- 29 days
- Class
- Class U
- Product code
- LIL
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 1 generation to K936115 (1995). 1 later device descends from it, 1 citing it directly.
- Root · 1 generation backK936115 Cat-600 Penile PlethysmographFarrall Instruments, Inc. · 1995
- This deviceK033126 Monarch 21 Penile Plethysmograph SystemBehavioral Technology, Inc. · 2003
- Descendant · cites it directly · 0 of its ownK052929 Preftest Professional SuiteLimestone Technologies, Inc. · 2006
Most influential descendants
Showing 1 of 1 · See all- K052929Preftest Professional SuiteLimestone Technologies, Inc. · 2006 · cites it directly0descendants
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −1 | K936115 | Cat-600 Penile Plethysmograph | Farrall Instruments, Inc. | 1995 | — |
| 0 (this device) | K033126 | Monarch 21 Penile Plethysmograph System | Behavioral Technology, Inc. | 2003 | — |
| +1 | K052929 | Preftest Professional Suite | Limestone Technologies, Inc. | 2006 | — |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2006 | 1 | 0 |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in LIL? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
- Candidate predicates for a device like this, rankedin the report
- Recall history across each candidate’s familyin the report
What was it cleared against? (1)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | K936115 | Cat-600 Penile PlethysmographSummary page 1…Penile Plethysmograph ClassificationName: Monitor, Penile Tumescence Predicate Device Device Name: CAT-600 Penile Plethysmograph, K936 115 Description of the Device MONARCH 21 Penile Plethysmograph consists of attached sensors, which measure penile tumescence. A la… | 1995 |
What descends from it? (1)
1 later device cites it directly; ranked here by how many devices descend from each in turn.
| Number | Device | Decided | Descendants |
|---|---|---|---|
| K052929 | Preftest Professional Suite | 2006 | 0 |
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- Its one ancestor has no recall.
- Of its descendants, K052929 (Limestone Technologies, Inc., 2006) has gone furthest, with 0 descendants of its own.
How does its category compare?
All LIL devicesLIL Monitor, Penile Tumescence: FDA decisions, review times, recalls and adverse event reports over 20 years.
FDA decisions per year · LIL
FDA has decided no LIL device since 2007.
Median 510(k) review, days · LIL
Too few LIL 510(k)s in any year since 2007 to give a median.
Recalls per year · LIL
No recall names LIL since 2007.
Adverse event reports per year · LIL
No MAUDE report names LIL since 2007.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 0 | — | 0 | 0 |
| 2008 | 0 | — | 0 | 0 |
| 2009 | 0 | — | 0 | 0 |
| 2010 | 0 | — | 0 | 0 |
| 2011 | 0 | — | 0 | 0 |
| 2012 | 0 | — | 0 | 0 |
| 2013 | 0 | — | 0 | 0 |
| 2014 | 0 | — | 0 | 0 |
| 2015 | 0 | — | 0 | 0 |
| 2016 | 0 | — | 0 | 0 |
| 2017 | 0 | — | 0 | 0 |
| 2018 | 0 | — | 0 | 0 |
| 2019 | 0 | — | 0 | 0 |
| 2020 | 0 | — | 0 | 0 |
| 2021 | 0 | — | 0 | 0 |
| 2022 | 0 | — | 0 | 0 |
| 2023 | 0 | — | 0 | 0 |
| 2024 | 0 | — | 0 | 0 |
| 2025 | 0 | — | 0 | 0 |
| 2026 | 0 | — | 0 | — |
What is it indicated for?
The MONARCH 21 system’s intended use is to measure sexual response to visual and auditory stimuli in male sexual offenders as an important part of evaluating individual treatment need and determining risk for recidivism.
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K033126 · printed Nov 6, 2026
Cite this page
510(k) Report. “K033126: Monarch 21 Penile Plethysmograph System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K033126
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026