Peek into your lover's backdoor with the Peephole Hollow Plug by Master Series.  This plug has a hollow center for lube tube insertion or for looking into.  Its tip is slightly tapered for easy insertion.  It has a flared base for anchoring and easy retrieval.  It's ideal for liquid play.  Use this plug with water based lubricant.

Small: 3.25 inches in total length, 2.5 inches insertable length, 1.55 inches in diameter.

Large: 3.9 inches in total length, 3 inches insertable length, 1.9 inches in diameter.