i don't have one, but i have calculated the length to be 2". this was done by measuring the length of the grip from a picture, and measuring the length of a 90-degree macroline fitting from that same picture, then measuring the length of a macroline fitting with a pair of digital calipers (this is the reference object), and then cross-multiplying.
i did this with two different pictures to confirm. the pictures were
this one and
this one. so, if the grip you're after is the one in those pictures, it's 2" long.