The 85w Bulbs are HUGE - they measure 28cm/11" long and 9cm/3.5" diameter and are equivalent to 425W. 

These bulbs will not fit all lights.  Please ask before purchase if you need advice. 

They DO fit our Kuhl Lite 30 and 120 (you CAN use four of these Studio Bulbs in the Kuhl Lite 120)

They DO fit our SoftBox Studio LitZ SB40 and SB50 (you CAN use four of these Studio Bulbs in the SoftBox Studio LitZ SB50)

They are NOT suitable for use in our standard Tabletop or Large Lights Set (we recommend our 30W 5000K TrumpetTop Bulbs for these)

Note - Lifespan given as a guide only